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667Mhz memory for 1505?

post #1 of 19
3/21/06 at 12:20am
Thread Starter 
I only see the 533Mhz memory as an option on the Dell site, but Crucial has 667Mhz memory listed on their site.

1) Will it make any difference whatsoever in performance?

2) Why isn't it on the Dell site?
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post #2 of 19
3/21/06 at 1:28am
It may be that Dell has a contract with a certain memory company. For toshiba it's kingston, and kingston doesnt yet make high capacity pc2-5300 667MHz memory (please correct me if i'm wrong). Thus, toshiba only offers 533 memory for the 667-capable laptop i bought.
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post #3 of 19
3/21/06 at 1:32am
thats not it.

dell always offers in the 15" and 12" laptops 1 level less memory than what it is capable of.

my 6000 a year ago came with 256 of ddr2.400, yet it is capable of using the 533. the 6400 is setup the same,

get some 533, you will be fine, there is no difference in the two. the 667 is faster, but has more relaxed timings, which currently slow it down.
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post #4 of 19
3/21/06 at 2:01am
My E1705 came with Samsung 533 Mhz Memory, but they did offer the 667 as an upgrade. I stuck with 533 because in Dual Channel mode it would make no difference.

The Dell.com site offers both types of memory but at an extra 75 dollars over the 533. not sure if it's worth that price difference.
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post #5 of 19
3/21/06 at 5:23am
www.dell.se (Sweden) does not have the 667 MHz memory for the 9400. Not any longer, that is. I know they had a month ago.

I wonder why.
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post #6 of 19
3/21/06 at 6:53am
Quote:
Originally Posted by m94mni
www.dell.se (Sweden) does not have the 667 MHz memory for the 9400. Not any longer, that is. I know they had a month ago.

I wonder why.
same here in Norway, when i ordered in february it was there. now it isnt :/
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post #7 of 19
3/21/06 at 10:07am
Quote:
Originally Posted by chevyrulz099
... the 667 is faster, but has more relaxed timings, which currently slow it down.
667's "relaxed" timings actually yeild the exact same latency as the "tighter" timings on 533:

CAS is measured in cycles, not in nanoseconds.
CAS 5 DDR2 667 actual latency = 1/667,000,000 (seconds) * 5 (cycles) = 7.49x10 ^ -9 seconds

CAS 4 DDR2 533 actual latency = 1/533,000,000 * 4 = 7.50x10 ^ -9

So both of these memories have the same latency of 7.5 nano seconds.

DDR2 667 (with CAS 5) provides the same latency as DDR2 533 (with CAS 4) but with higher bandwidth, so it's not going to be slower at all.

There is however 667 ram with a CAS of 4 (though I haven't seen pricing on it yet). So that would be the fastest option.

However, it is also worth noting that you will not see a performance improvement by going from 533 (cas 4) to 667 (cas 5) memory on a yonah laptop as long as you are running the system in dual channel mode.

Though you have increased memeory bandwidth from 1066MHz to 1333MHz (effective), both are still limited by the 667MHz FSB connecting them to the processor.
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post #8 of 19
3/21/06 at 10:47am
Thread Starter 
Wow! Thanks for the explanations, guys! So we won't even be able to take full advantage of 533 or 667 until the FSB increases past 1066Mhz?
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post #9 of 19
3/21/06 at 10:58am
If you're running the ram in dual channel mode, yes, you aren't coming near the throughput of the ram
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post #10 of 19
3/21/06 at 12:22pm
Quote:
Originally Posted by DarthPierce
If you're running the ram in dual channel mode, yes, you aren't coming near the throughput of the ram
Won't latency be an issue if your FSB is mismatched with the memory speed? DDR2 667 is perfectly matched with the FSB of Yonah. I think 533 might have to add latency to make them match. I guess unless someone runs benchmarks between the two on a Yonah platform, no one will know.
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post #11 of 19
3/21/06 at 12:30pm
Quote:
Originally Posted by magbarn
Won't latency be an issue if your FSB is mismatched with the memory speed? DDR2 667 is perfectly matched with the FSB of Yonah. I think 533 might have to add latency to make them match. I guess unless someone runs benchmarks between the two on a Yonah platform, no one will know.
The same thought had occured to me, but from benchmarks I've seen, there is very little difference.
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post #12 of 19
3/21/06 at 2:22pm
yea the worth of 667 over 533 is neglible as of today.

one day, it will be worth the faster memory though, just not today
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post #13 of 19
3/21/06 at 2:27pm
and realistically that day is well over a year away. This time next year, top end laptops will have merom with an 800MHz FSB.... Which STILL won't even come close to using 533MHz dual channel ram to its potential. (533 dual channel ~1066MHz). I wouldn't expect faster than 800MHz FSB on intel laptops till at least 4Q07 if not later than that.
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post #14 of 19
3/21/06 at 5:19pm
Is the difference still negligible if using a hypermemory card in the 1505 (does it use the same bus)?
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post #15 of 19
3/21/06 at 5:25pm
I am unclear on how much memory bandwidth is used by hypermemory cards. I suspect that you may be able to see an advantage to the 667 ram when using an x1400 for example. I have not seen any benchmarks to prove or disprove that statement, however.
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post #16 of 19
3/21/06 at 11:53pm
trust me youll be fine with the 533, just get it and save money;
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post #17 of 19
3/22/06 at 4:20am
Quote:
Originally Posted by chevyrulz099
trust me youll be fine with the 533, just get it and save money;
QFT
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post #18 of 19
3/22/06 at 8:28am
Thread Starter 
Sorry, what's QFT?
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post #19 of 19
3/22/06 at 8:40am
Quote:
Originally Posted by jacksonian
Sorry, what's QFT?
Quoted For Truth
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